This application generally relates to the field of improving passenger safety in the event of a front end collision, and, more particularly, relates to achieving an improved crash pulse through the detachment of a vehicular sub-frame.
Crash severities, during front-end collisions in vehicles, are observed to increase as the length of a front end, primarily including the hood, decreases. Most vehicle owners and manufacturers desire for a shorter front-end in modern vehicular design. Crash severities, however, for such vehicles, maintaining a conventional design, may generally be very high, and expensive safety and restraint systems may not prove sufficient to provide adequate protection to vehicular occupants. Particularly, a short front-end, in conventional designs, provides limited advantage to abide by federally mandated occupant safety requirements.
Detachable sub-frames have thus been developed in conventional vehicle safety systems to overcome the disadvantages of short front-ends. During a frontal collision, such detachments, as noted, aim to provide an improved crash pulse by utilizing additional crush space available under a vehicle. Construction of such a sub-frame includes a bolt, or a series of bolts, that fastens a rear portion of a sub-frame to an underbody of a vehicle. During collisions, the bolts are designed to break according to a predetermined threshold, allowing the rear of the sub-frame to unfasten and slide under the vehicle's underbody. Such sliding allows optimal space utilization, and the attainment of a more effective crash pulse, mitigating the transfer of the collision's shock to the vehicular occupants.
In real life accidents, however, a vehicle's loading conditions may vary, which causes the bolts to break at an inappropriate time, causing an improper restraint response in a dangerous collision. In addition, breaking of such bolts also depend upon the bolts' diameter, failure strength at which they are designed, operating temperatures, etc. Such limitations in conventional designs may thus result in an increased possibility of injuries to the vehicle's occupants.
An alternate method and system is thus proposed in the present disclosure, which includes a change in the design and working of the fasteners applied in sub-frames employed in conventional vehicles. Such method and system, particularly aims to achieve a more effective crash pulse deployment in vehicles during a crash.